极限分析法求解含软弱夹层边坡稳定性

软弱夹层对边坡的稳定性影响显著，目前设计中通常采用极限平衡法计算边坡的稳定性，其在求解中需要建立多个平衡方程. 为了分析含软弱夹层边坡的稳定性，首先，采用极限分析法建立了计算模型；其次，通过极限平衡法验证了求解的准确性；最后，分析了荷载、夹层形状、夹层强度等对稳定性的影响. 研究结果表明:边坡安全系数随着外荷载强度的增大而减小，其中，当加速度放大系数由1.0增大为1.6时，安全系数由1.20降为0.89；当外荷载频率越大时，边坡越易提前产生破坏；软弱夹层形状对边坡安全系数影响显著，特别是当其靠近坡顶与坡面时；安全系数随着软弱夹层摩擦角与黏聚力的减小而近似线性降低，其中，当黏聚力由9 kPa降为5 kPa时，安全系数降低约30%. 

Stability Analysis of Slopes with Weak Layers Using Limit Analysis Method

Weak layers have a significant effect on the stability of slopes. The stability of slopes is usually calculated by the limit equilibrium method in current designs, in which multiple equilibrium equations need to be established and solved. Compared with the limit equilibrium method, the limit analysis method is more rigorous, and requires only one energy equation to be solved. In order to analyze the stability of slopes with weak interlayers, a stability calculation model was established by the limit analysis method, and then the accuracy of the solution was verified by the limit equilibrium method. Finally, the effects of load, weak layer shape, and weak layer strength on stability were analyzed. The results show that the slope safety factor decreases with an increase in the load intensity. When the acceleration amplification factor increases from 1.0 to 1.6 the safety factor decreases from 1.20 to 0.89. With a higher frequency of the external load, the slope is easier to be damaged in advance. Besides, the shape of the weak layer has a significant effect on the slope safety factor, especially when it is close to the top and surface of the slope. The safety factor decreases approximately linearly with the decrease of the friction angle and cohesion of weak layers. When the cohesion strength decreases from 9 kPa to 5 kPa, the safety factor decreases by about 30%.